A feeding trial was conducted with an objective to compare the utilization of groundnut cake, soybean meal and detoxified castor bean meal as protein supplements in growing broiler rabbits. Eighteen weaned broiler rabbits (6-7 week old) were randomly divided into three groups, wherein, each group comprised six rabbits. The experimental rabbits of group 1 (T1) were fed composite diet containing groundnut cake (GNC), while experimental groups received composite diet containing either soybean meal (SBM) (T2) or salt (2%, w/w) treated CBM (S-CBM) (T3) to substitute 100% GNC nitrogen moiety of conventional diet (T1). The experimental period lasted for 60 days. The DM intake (g/d) (100.52-T3, 100.56- T1 and 108.1- T2) did not differ significantly among rabbits on different dietary regimens. The average daily gain (ADG) (g/h/d) was significantly (P < 0.05) higher for T2 group receiving SBM based diet (13.36) as compared to the group receiving GNC (T1- 10.56) or SCBM (T3- 10.17) based diets. However, the difference in ADG between T1 and T3 was non significant. In the present study, there was a linear increase in body weight of rabbits till the end of feeding trial. Further, the efficiency of feed utilization for weight gain (g DM intake / g gain) (8.39- T2, 9.62- T1 and 10.01- T3) revealed no significant difference among treatments and so also for the digestibility of the DM, Organic matter (OM), crude protein (CP), ether extract (EE) and nitrogen free extract (NFE). The rabbits of all the treatments digested fibre fractions similarly without any significant difference among treatments. Thus, soybean meal and castor bean meal, after processing with common salt, were found to be satisfactory protein substitutes to spare scarce and costly oil seed cakes for economical rabbit production.